Objective To explore the changes of ultrastructural characteristics including interstitial space dilation(ISD) and the number of desmosome in non-erosive gastroesophageal reflux disease(NERD)with abnormal and normal oesophageal acid exposure.Methods Nineteen patients with(abnormal) oesophageal acid exposure,20 with normal oesophageal acid exposure,10 with reflux(esophagitis)(RE) and 10 asymptomatic controls,classified on the basis of pH-metry,underwent(endoscopy.) Three biopsies were taken from the normal mucosa for light microscopy and transmission(electron microscopy) evaluation.ISD was measured and the number of desmosome in the intercellular spaces was calculated by using a digital scanner from photomicrographs of the specimens.The above two markers were compared with each other among the above groups.Results There was no significant difference in the mean score of the interstitial space between NERD and RE patients [(2.21?0.68)?m versus(2.39?0.42)?m,P0.05)].The mean score of the interstitial space of the control was(0.63(?0.21))?m,much lower than those of NERD and RE patients(P0.01).There was a significant(difference) in ISD between NERD with abnormal oesophageal acid exposure and normal oesophageal acid(exposure) [(2.45?0.67)?m versus(1.91?0.67)?m,P0.05].The mean numbers of desmosome in the intercellular space of the NERD and RE patients were(0.141?0.043) entries/?m~2 and(0.124(?0.044)) entries/?m~2,respectively,significantly lower than those of the controls [(0.221?0.031)(entries/?m~2].) But no significant differences were observed between the RE and the NERD patients(P0.05).Conclusions The interstitial space of esophageal mucosa in the NERD patients is dilated as in the RE.In NERD patients,the dilation of interstitial space is associated with abnormal acid exposure.The numbers of desmosome may also be a marker of esophageal mucosal injury of NERD.

Objective To evaluate the accuracy of different methods in detecting free amino acids in plasma.Method 40 blood samples from healthy volunteers were analyzed by an automatic amino acid analyzer ( Li+system) and the results compared with previous reports using other analyzers.Results The results ob-tained by this analyzer for major amino acids [asparagine (Asn), glutamic acid (Glu), glutamine (Gln), valine (Val), tyrosine (Tyr), phenylalanine (Phe), ornithine (Orn), arginine (Arg)] were similar with those previously reported using other amino acid analyzers ( all P>0.05 ) and liquid chromatography tandem-mass spectrometry (LC-MS/MS) (all P>0.05).Except for Glu and Tyr, the results for major amino acids showed large deviation compared to the results from high performance liquid chromatography ( HPLC) ( all P<0.05).Conclusion The amino acid analyzer (Li+) and LC-MS/MS (iTRAQ kit) could accurately detect free amino acids in plasma.

Objective To explore the shielding effects of 1-4 layers of lead aprons (LPs) and body shielding devices (BSDs) against stray radiation (SR) outside the electron beam field of 6-15 MeV.Methods JR-115B LiF TLDs were used to measure the stray radiation doses (SRDs) to the patient undergoing treatment,before and after being shielding,for different distances,different energies,different applicators,variable layers of LPs,and different thickness of body shielding devices (BSDs),respectively,along long calculating and comparing the shielding ratios of LPs and BSDs against SR.Results When the applicator (10 cm × 10 cm) is unchanged,the shielding ratio increased with the increased distance from measuring point (r =0.717,P ＜ 0.05) and decreased with the increased electron energy (r =-0.678,P ＜ 0.05);when the energy was constant,there was no correlation between the shielding ratio and the size of applicator (P ＞ 0.05);For lower energy electron beam of 6 and 9 MeV,the shielding ratio for 1 mm Pb-BSD was slightly higher than that for 2 layers of LA (t =2.519,2 662,P ＜ 0.05),ranging from 81.5％ to 95.3％ and 55.4％ to 84.6％,respectively.For 12 and 15 MeV higher energy electron beam,the shielding ratio for 2 mm Pb-BSD was slightly higher than that for 4 layers of LA (t=3.768,7.934,P＜0.05),ranging from 64.6％ to 93.4％ and 51.1％ to 92.4％,respectively.Conclusions LAs or BSDs are availavle for effectively reducing the doses from stray radiation,and may help reduce the secondary risks from stray radiation.BSDs have more obvious advantages than LPs with regard to shielding effect.

Objective To explore the relationship between the osteonecrotic volume (lesion size), angle and the index of necrotic extent on the femoral head. Methods Fifty-one hips in 39 patients with non-traumatic avascular osteonecrosis on the femoral head were divided into 12 equal segments from the head to the neck junction (a turning point of the spherical curve of the head) with whole hip displacement, each with 30 degrees on a coronal plane of weight-bearing surface. The osteonecrotic angle of the arc of each necrotic segment from the center of the femoral head was measured at the point of one- to 12-o'clock on imaging of two dimensional reconstruction of computerized tomography (CT) scans and anteroposterior and lateral radiographs. Necrotic volume on each segment of the femoral head was calculated with fluid displacement method. The index of osteonecrotic extent on the femoral head was calculated using direct anatomical measurements. Results Osteoneerotic volume on the femoral head at the point of 12- to one-o'clock on coronal plane was (74. 5 ± 7.4)% of the sphere equivalent of the whole femoral head, which was positively correlated to its necrotic angle [ (41.9±8. 3) degrees] at the point of one-o'clock on the plane, with a coefficient of correlation of 0. 843, and that at the point of one- to two-o'clock on the plane was (73.7 ±0. 4) %, which was positively correlated to its necrotic angle [ (41.9 ± 1.8) degrees] at the point of two-o'clock, with a coefficient of correlation of 0. 543. Osteonecrotic volume on the point of 11- to 12-o'cleck was (83.6±8.6)%, and the necrotic angle at the point of 12-o'clock was (44. 9±3.9) degrees, which were positively correlated each other, with a coefficient of correlation of 0. 701 (P <0. 01 ). Osteonecrotic volume on the femoral head was positively correlated to its necrotic angle , modified index of necrotic extent, index of necrotic extent and Kerboul conjugated necrotic angle, with coefficients of correlation of 0. 798, 0. 701, 0. 377 and 0. 398 ( P < 0. 01 ), respectively, at the point of one o' clock. Conclusions Measurements of osteonecrotic volume was positively correlated to the index of necrotic extent and necrotic angle on the femoral head, respectively. Necrotic angle on the plane at 30-degree of the trochanter on the femoral head can well reflect its necrotic volume.

Objective To analyse the clinical features of patients with gastroesophageal reflux disease(GERD)who had scores＜12 using reflux diagnostic questionnaires(RDQ).Methods A comparative and retrospective study was carried out in 148 GERD patients.Among whom 22 patients had low RDQ score(＜12)and 126 patients had high RDQ score(≥12).The differences in heart burn,substantial chest pain,regurgitation,severity and frequency of food reflux between two groups were compared.Nevertheless,the atypical symptoms such as chest distress.abnormal sensation of regurgitation or food reflux was significantly lower in patients with RDQ＜12 than those with RDQ≥accounted for 60.28%of the total RDQ score,whereas the heart burn,regurgitation and food reflux atypical symptom of chest distress was found in 13 patients(59.09%),abnormal sensation of throat in 8 patients(36.36%).cough and asthma in 3 patients(13.63%),headache in 5 patients(22.72%),belching in 9 patients(40.90%),aypnia in 8 patients(36.36%),and anxiety in 6 patients(27.27%).Conclusion RDQ is insensitive to those who have chest pain with no obvious symptom of heart burn,regurgitation or food reflux as well as those with atypical symptom beyond the RDQ.

Objective To investigate the effect of super-selective intracoronary administration on acute myocardial in farction patients.Methods A total of 240 patients with ST-segment elevation myocardial infarction who received emergency percutaneous coronary intervention in our department from March 2012 to January 2014 were selected and divided into the intravenous drug administration group (n=77),the conventional intracoronary drug administration group (n=81) and the super-selective intracoronary drug administration group (n=82).Parameters,including the Thrombolysis in Myocardial Infarction (TIMI) classification,ST segment resolution after operation,peak values of creatine kinase MB (CK-MB) and troponin-I (cTn-I),left ventricular ejection fraction,left ventricular end-diastolic diameter (LVEDD),major adverse cardiovascular events and bleeding events,were compared between the groups.Results There were no significant differences in TIMI flow grade between the three groups (x2 =0.14,P=0.529).The percentage of patients with complete ST segment resolution after operation was higher in the super-selective intracoronary drug administration group than in the intravenous drug administration and conventional intracoronary drug administration groups (74.4％ vs.62.3％,61.7％,x2 =8.24,P＜0.05).Peak values of CK-MB and cTn-I were lower in the super-selective intracoronary drug administration group than in the other groups (P＜0.05).There were no significant differences in left ventricular ejection fraction and LVEDD between the three groups after operation,but left ventricular ejection fraction and the incidence of angina pectoris significantly improved in the super-selective intracoronary drug administration group than in the other groups after a three month follow-up (P＜0.05).There were no significant differences in target lesion revascularization,nonfatal myocardial infarction and druginduced thrombocytopenia between the three groups (P ＞ 0.05).Conclusions Super-selective intracoronary drug administration can significantly enhance cardiac function and alleviate angina pectoris in patients with acute myocardial infarction,and should be a recommended method.

Objective: To clarify the predictive value for long-term prognosis of GRACE score and SYNTAX score in patients with non-ST elevation acute coronary syndrome (NSTE-ACS).
Methods: A total of 784 NSTE-ACS patients treated in our hospital from 2009-01 to 2014-01 were retrospectively studied. According to the treatment, the patients were divided into 3 groups: Medication group,n=410, Stent group,n=325 and CABG group,n=49. Based on 2 scoring systems, the patients were divided into another 3 groups: Low risk group, Medium risk group and High-risk group. The relationship between GRACE score and SYNTAX score was studied by Pearson correlation analysis, survival analysis was conducted by Kaplan-Meier method, univariate and multivariate analysis were performed by Cox proportional hazard model, and the area under curve (AUC) of ROC analysis was used to compare two methods.
Results: All 784 patients completed the follow-up study at the median of 47.7 months. Pearson correlation analysis showed that there was a weak positive correlation between GRACE score and SYNTAX score (r=0.40,P<0.01). Survival analysis presented that by GRACE score system, the MACE occurrence rates in Low risk group, Medium risk group and High-risk group were elevated accordingly as 13.81%, 23.64% and 36.55% respectively. And by SYNTAX system, MACE occurrence rates in Medium risk group and High-risk group were 39.29% and 37.93%, which were both higher than that in Low risk group (23.99%), while the scores between Medium and High risk groups were similar,P>0.05. Cox proportional hazard model and ROC analysis indicated that GRACE and SYNTAX scores had the important predictive value for lone term prognosis of NSTE-ACS. ROC analysis of GRACE score, SYNTAX score, the combination of GRACE and SYNTAX scores showed that 3 of them all had good predictive value for MACE occurrence, three of 95% CI had signiifcant overlapping without statistic differences.
Conclusion: GRACE score and SYNTAX score are related, both of them have important while similar predictive value for long term prognosis in NSTE-ACS patients, the combination of 2 scores cannot increase the predictive value. GRACE score is appropriate for the risk stratiifcation in NSTE-ACS patients.

Cell microencapsulation aims to wrap the living target cells by one or several materials with good biological compatibility and semipermeable membrane properties.Cell microencapsulation not only can achieve immune isolation and prevent the attacks by macromolecular immunes and immune cells,but also can allow the free access of metabolites,small molecule nutrients and bioactive substances to the microcapsule.With the continuous progress of interdisciplinary technologies,cell microencapsulation shows increasing application prospects of making up a variety of limitations of organ transplantation.Moreover,with the development and maturation of cell microencapsulation,it has shown a strong advantage in regenerative medicine,which will certainly promote the rapid development of artificial cells and artificial organs.In this paper,the preparation of cell microcapsules,the effects of the outer membrane of microcapsules on immunological macromolecules and cytokines,the immunogenicity of the outer membrane,and the representative applications of cell microencapsulation were summarized.

BACKGROUND:Minipigs are often used in research fields such as skin injury,vascular trauma and cosmetic medicine because they are highly similar to human beings in terms of skin tissue structure and cardiovascular system.Hydrogel as a wound repair drug possesses a variety of excellent physicochemical properties such as strong water retention and adhesion,which can provide isolation moisturization and drug release for wounds. OBJECTIVE:To summarize and conclude the progress of the application of trauma models for different experimental purposes of hydrogel therapy for minipigs,to reveal the development status of various types of minipig trauma models,to analyze the deficiencies of minipig trauma models at the present stage. METHODS:The relevant articles published in Web of Science database and CNKI database from the establishment of each database to 2023 were checked,using"piglet,miniature pig,minipig,miniature pig;gel,hydrogel;trauma,injury,wound,lesion,incision"as Chinese search terms and"Miniature Swine,Miniature pig,minipig;gel,hydrogel;injury,wound,lesion,incision"as English search terms.A total of 438 Chinese and English documents were retrieved,and 59 documents were included in the study through the inclusion and exclusion criteria. RESULTS AND CONCLUSION:(1)At present,the main models used clinically for trauma repair are large animal species(dogs and pigs),rabbits,and rodents(rats and mice).Because the skin structure of the minipig is more like that of humans,the minipig is the most ideal animal model for trauma repair.(2)In the in-vitro skin injury model,skin defect model is the basic wound model,which can be divided into full skin defect model and medium-thickness skin defect model according to the depth of the wound defect.Burn wound model and infected wound model are multidimensional models with hot metal scald and bacterial culture imposed on the basis of the skin defect model,which have the advantages of high safety coefficient and low operation difficulty.(3)In the in-vivo trauma repair model,mini-pigs are used as esophageal cricothyrotomy model which is more in line with the pathological state of clinical diseases.Mini-pigs are used in the gastric perforation and vascular hemostasis model,which can visually demonstrate the stronger organ adhesion,hemostatic properties and tissue regeneration-promoting effects of the hydrogel.(4)The specific parts of the pig also has the corresponding mode of use:pig ear is usually used to evaluate the hydrogel drug delayed-release effect.Porcine cellular proteins and pig skin collagen are mostly used to prepare composite hydrogels of tissue origin.

Objective:To analyze the current situation and influencing factors of work-related musculoskeletal disorders (WMSDs) among scientific researchers in a computer workstation of a high-tech aerospace enterprise, and to provide data support for the improvement of occupational health management policies in this type of enterprise.Methods:From March to April 2023, using convenient sampling method, 1398 scientific researchers using computer workstations in an aerospace high-tech enterprise in Beijing were selected as the research subjects. The incidence of WMSDs in various parts of the body was investigated by using the Musculoskeletal Disorders Questionnaire, and the influencing factors of WMSDs in neck, lower back, shoulder and upper back were analyzed by logistic regression.Results:The total incidence of WMSDs was 55.4% (774/1398) in the scientific researchers who used computer workstations. The top 4 body parts in WMSDs incidence were neck (24.3%, 340/1398), lower back (20.4%, 285/1398), shoulder (18.7%, 262/1398), upper back (12.7%, 177/1398). The results of multivariate logistic regression analysis showed that feeling slightly tired and tired after work, setting a rest/break time of 10 to 15 min before the next continuous job, and operating computer for 2 to 4 hours and >4 hours were the influencing factors for the occurrence of neck WMSDs ( OR=3.08, 1.90, 0.60, 2.00, 1.49, P<0.05). Female, 5-<10 years of working experience, feeling slightly tired, tired and very tired after work, operating computer for 6-<8 hours and 8-10 hours a day were all the influencing factors for the occurrence of WMSDs in the lower back ( OR=1.82, 0.64, 2.95, 1.80, 1.61, 1.82, 1.73, P<0.05). Female, feeling slightly tired and tired after work were the influencing factors of shoulder WMSDs occurrence ( OR=2.42, 2.09, 2.00, P<0.05). Female, 5-<10 years, 10-15 years of working age, 1-3 times of physical exercise/quarter, feeling slightly tired, tired and very tired after work were the influencing factors for the occurrence of upper back WMSDs ( OR=2.76, 2.19, 2.78, 0.48, 4.20, 2.66, 2.19, P<0.05) . Conclusion:The incidence of WMSDs among scientific researchers in computer workstations of aerospace high-tech enterprises is high, which is closely related to individual characteristics and workstation usage characteristics. Measures should be taken to prevent and improve the WMSDs status of scientific researchers.